Databricks Certified Data Engineer Associate Practice Test 39
Question 380
At Public water district, the pipeline flow metrics workflow depends on pipeline_flow_metrics_urban. Engineers report that engineers refer to pipeline_flow_metrics_urban by an ambiguous two-part name and access the wrong environment; the evidence is that the same schema and table names exist under development and production catalogs. They require that code must resolve a single governed production object. The team has not selected a remedy. It first needs evidence that distinguishes the actual dependency or data fault. Which pre-change diagnostic will resolve the uncertainty?
- Use catalog.schema.table identifiers with explicit Unity Catalog ownership
- Depend on each user's default catalog to identify the production table at Public water district
- Change the pipeline to explicit three-level names and test in a staging job
- Check current catalog, schema and resolved fully qualified table for pipeline_flow_metrics_urban
Explanation
Correct Answer
D:Check current catalog, schema and resolved fully qualified table for pipeline_flow_metrics_urban directly investigates the evidence (the same schema and table names exist under development and production catalogs) and distinguishes possible causes of engineers refer to pipeline_flow_metrics_urban by an ambiguous two-part name and access the wrong environment. It establishes what must be corrected without assuming a fix before verifying the stated business requirement: code must resolve a single governed production object.
Incorrect Answers
A:Use catalog.schema.table identifiers with explicit Unity Catalog ownership is a plausible lasting design once chosen, but it does not perform the required pre-change investigation at this stage. In the pipeline_flow_metrics_urban scenario, the observed evidence is that the same schema and table names exist under development and production catalogs; the requirement remains: code must resolve a single governed production object.
B:Implicit current-catalog resolution makes production writes ambiguous. The proposed action (Depend on each user's default catalog to identify the production table at Public water district) does not meet the requirement that code must resolve a single governed production object, nor does it constitute the required pre-change investigation.
C:Change the pipeline to explicit three-level names and test in a staging job may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the required pre-change investigation, especially given the evidence that the same schema and table names exist under development and production catalogs.
Question 381
At National farm supplier, the quality expectations pipeline workflow handles harvest purchase orders. The problem is that harvest_purchase_orders_west silver records pass ingestion despite negative billed quantities. Evidence: validation sample identifies impossible values in otherwise well-formed JSON. Constraint: bad records need a defined reject/quarantine policy without hiding valid data. The new approach is deployed. The current task is to prove correct output and authorized behavior, not just successful installation. Which test should pass before the new flow is accepted?
- Roll out expectation checks and a quarantine audit before enforcing production policy
- Delete invalid rows silently and report the entire batch as error-free at National farm supplier
- Quantify invalid predicate occurrences and source impact for harvest_purchase_orders_west
- Inject invalid rows and verify correct drop, fail or quarantine behavior
Explanation
Correct Answer
D:Inject invalid rows and verify correct drop, fail or quarantine behavior directly tests the behavior that should change after the correction. With the observed evidence (validation sample identifies impossible values in otherwise well-formed JSON), the acceptance result must demonstrate actual data or permission correctness, while retaining the requirement that bad records need a defined reject/quarantine policy without hiding valid data.
Incorrect Answers
A:Roll out expectation checks and a quarantine audit before enforcing production policy may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the post-change acceptance test, especially given the evidence that validation sample identifies impossible values in otherwise well-formed JSON.
B:Silent loss hides quality issues and masks upstream defects. The proposed action (Delete invalid rows silently and report the entire batch as error-free at National farm supplier) does not meet the requirement that bad records need a defined reject/quarantine policy without hiding valid data, nor does it constitute the post-change acceptance test.
C:Quantify invalid predicate occurrences and source impact for harvest_purchase_orders_west could clarify the original fault, but the available evidence already establishes its scope; it is not the post-change acceptance test now requested. The harvest_purchase_orders_west workflow still requires that bad records need a defined reject/quarantine policy without hiding valid data.
Question 382
Consider the class_enrollment_data_west workload at International language school: class_enrollment_data_west has one row per order with an array of purchased items. Inspection found that the silver table counts order-level rows as product-level units. The governed outcome must ensure that downstream inventory reporting needs one row per element with its parent key. The team has not selected a remedy. It first needs evidence that distinguishes the actual dependency or data fault. Which evidence-gathering action should precede an architectural change?
- Split the serialized array text on commas without parsing JSON at International language school
- Pilot nested extraction and test orders with multiple items
- Apply explode or explode_outer deliberately while retaining the order ID
- Inspect array structure and null or empty-array cases for class_enrollment_data_west
Explanation
Correct Answer
D:Inspect array structure and null or empty-array cases for class_enrollment_data_west directly investigates the evidence (the silver table counts order-level rows as product-level units) and distinguishes possible causes of class_enrollment_data_west has one row per order with an array of purchased items. It establishes what must be corrected without assuming a fix before verifying the stated business requirement: downstream inventory reporting needs one row per element with its parent key.
Incorrect Answers
A:String splitting is not a typed nested-array transformation. The proposed action (Split the serialized array text on commas without parsing JSON at International language school) does not meet the requirement that downstream inventory reporting needs one row per element with its parent key, nor does it constitute the required pre-change investigation.
B:Pilot nested extraction and test orders with multiple items may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the required pre-change investigation, especially given the evidence that the silver table counts order-level rows as product-level units. This matters here because consider the class_enrollment_data_west workload at International language school: class_enrollment_data_west has….
C:Apply explode or explode_outer deliberately while retaining the order ID is a plausible lasting design once chosen, but it does not perform the required pre-change investigation at this stage. In the class_enrollment_data_west scenario, the observed evidence is that the silver table counts order-level rows as product-level units; the requirement remains: downstream inventory reporting needs one row per element with its parent key.
Question 383
At Independent cinema group, the skewed join key workflow handles ticket transactions. The problem is that ticket_transactions_south join hangs on one task while almost every task completes quickly. Evidence: Spark UI reveals one partition contains most rows for a hot customer key. Constraint: optimization must preserve all correct joined rows. The new approach is deployed. The current task is to prove correct output and authorized behavior, not just successful installation. Which test should pass before the new flow is accepted?
- Test skew-aware join on representative hot and cold key samples
- Verify exact join output and reduced straggler duration
- Drop the most frequent business key to balance partitions at Independent cinema group
- Profile key frequencies and straggler task metrics for ticket_transactions_south
Explanation
Correct Answer
B:Verify exact join output and reduced straggler duration directly tests the behavior that should change after the correction. With the observed evidence (Spark UI reveals one partition contains most rows for a hot customer key), the acceptance result must demonstrate actual data or permission correctness, while retaining the requirement that optimization must preserve all correct joined rows.
Incorrect Answers
A:Test skew-aware join on representative hot and cold key samples may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the post-change acceptance test, especially given the evidence that Spark UI reveals one partition contains most rows for a hot customer key.
C:Dropping a hot key loses legitimate data. The proposed action (Drop the most frequent business key to balance partitions at Independent cinema group) does not meet the requirement that optimization must preserve all correct joined rows, nor does it constitute the post-change acceptance test.
D:Profile key frequencies and straggler task metrics for ticket_transactions_south could clarify the original fault, but the available evidence already establishes its scope; it is not the post-change acceptance test now requested. The ticket_transactions_south workflow still requires that optimization must preserve all correct joined rows.
Question 384
The pollution_measurements_north pipeline at Air quality nonprofit has this failure: the pollution_measurements_north SQL aggregation runs slowly on eligible compute despite a stable dataset. The team observed that query profiling identifies CPU-bound SQL operations with little external I/O. Business requirement: performance changes must be measured at equivalent compute and data volume. The failure and requirements have been diagnosed; the team must select the lasting pipeline or governance approach. What lasting solution should be selected for the verified conditions?
- Track query latency and cost-per-run after moving pollution_measurements_north
- Baseline SQL plan, engine configuration and resource use for pollution_measurements_north
- Assume Photon eliminates every network, skew and access-permission problem at Air quality nonprofit
- Evaluate Photon-capable compute for supported SQL and DataFrame workloads
Explanation
Correct Answer
D:Evaluate Photon-capable compute for supported SQL and DataFrame workloads is the intended durable approach for pollution_measurements_north: it addresses the verified problem (the pollution_measurements_north SQL aggregation runs slowly on eligible compute despite a stable dataset) while preserving the required behavior (performance changes must be measured at equivalent compute and data volume). A diagnostic or monitoring step alone would not create this target-state behavior.
Incorrect Answers
A:Track query latency and cost-per-run after moving pollution_measurements_north would help detect future recurrence, but metrics alone do not deliver the target approach. The pollution_measurements_north requirement is that performance changes must be measured at equivalent compute and data volume.
B:Baseline SQL plan, engine configuration and resource use for pollution_measurements_north could clarify the original fault, but the available evidence already establishes its scope; it is not the target approach now requested. The pollution_measurements_north workflow still requires that performance changes must be measured at equivalent compute and data volume.
C:An execution engine cannot cure unrelated input or authorization constraints. The proposed action (Assume Photon eliminates every network, skew and access-permission problem at Air quality nonprofit) does not meet the requirement that performance changes must be measured at equivalent compute and data volume, nor does it constitute the target approach.
Question 385
The student_registration_records_east pipeline at Education access provider has this failure: student_registration_records_east notebook hardcodes a development catalog and writes there during production runs. The team observed that job run settings differ from values embedded in the notebook code. Business requirement: the same notebook must respect runtime environment configuration. The new approach is deployed. The current task is to prove correct output and authorized behavior, not just successful installation. What test most directly proves the requirement is satisfied?
- Remove hardcoded target paths and test parameterized notebook invocation
- Run dev and prod parameters and confirm each writes only to its own catalog
- Identify job parameter keys and where student_registration_records_east notebook resolves the catalog
- Edit the source notebook by hand every time the job changes environment at Education access provider
Explanation
Correct Answer
B:Run dev and prod parameters and confirm each writes only to its own catalog directly tests the behavior that should change after the correction. With the observed evidence (job run settings differ from values embedded in the notebook code), the acceptance result must demonstrate actual data or permission correctness, while retaining the requirement that the same notebook must respect runtime environment configuration.
Incorrect Answers
A:Remove hardcoded target paths and test parameterized notebook invocation may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the post-change acceptance test, especially given the evidence that job run settings differ from values embedded in the notebook code.
C:Identify job parameter keys and where student_registration_records_east notebook resolves the catalog could clarify the original fault, but the available evidence already establishes its scope; it is not the post-change acceptance test now requested. The student_registration_records_east workflow still requires that the same notebook must respect runtime environment configuration.
D:Manual code edits are not reproducible parameterization. The proposed action (Edit the source notebook by hand every time the job changes environment at Education access provider) does not meet the requirement that the same notebook must respect runtime environment configuration, nor does it constitute the post-change acceptance test.
Question 386
At Regional sporting venue, the SQL warehouse suitability workflow handles admission scan events. The problem is that BI users query admission_scan_events_delta through engineering notebook compute with unpredictable startup and permissions. Evidence: query history shows short read-only dashboards competing with development Spark sessions. Constraint: analysts need governed SQL concurrency and stable refresh latency. The first acceptance run passed. The current task is to detect future regressions and changes over time. Which monitoring approach will detect newly emerging defects?
- Run representative concurrent queries and compare latency and spend
- Grant BI users unrestricted notebook cluster administration at Regional sporting venue
- Serve the BI workload on an appropriately sized SQL warehouse with Unity Catalog access
- Monitor warehouse queuing, idle use and dashboard refresh failures for admission_scan_events_delta
Explanation
Correct Answer
D:Monitor warehouse queuing, idle use and dashboard refresh failures for admission_scan_events_delta creates recurring visibility into the failure mode (BI users query admission_scan_events_delta through engineering notebook compute with unpredictable startup and permissions). Unlike a single successful test, the measure can reveal drift, lag, or new failures after later source and deployment changes while analysts need governed SQL concurrency and stable refresh latency.
Incorrect Answers
A:Run representative concurrent queries and compare latency and spend is a one-time acceptance check. It does not supply continuing operational detection for admission_scan_events_delta; a passing test cannot substitute for the specific task now required.
B:Broad compute administration is not necessary to query governed bi data. The proposed action (Grant BI users unrestricted notebook cluster administration at Regional sporting venue) does not meet the requirement that analysts need governed SQL concurrency and stable refresh latency, nor does it constitute continuing operational detection.
C:Serve the BI workload on an appropriately sized SQL warehouse with Unity Catalog access is a plausible lasting design once chosen, but it does not perform continuing operational detection at this stage. In the admission_scan_events_delta scenario, the observed evidence is that query history shows short read-only dashboards competing with development Spark sessions; the requirement remains: analysts need governed SQL concurrency and stable refresh latency.
Question 387
A data engineer at Satellite imagery startup is responsible for land-cover observations. The liquid clustering maintenance issue is that land_cover_observations_south Delta queries slow after the filter distribution changes. The supporting evidence is that query profile shows increased file scanning despite healthy worker utilization. The engineer must ensure that performance optimization must adapt to predicate patterns. The target approach is approved. The current task is to introduce it safely with bounded scope and rollback. What is the safest migration or deployment sequence?
- Choose suitable liquid clustering keys and supported optimization maintenance
- Compare representative query scan metrics and results before and after
- Add a new physical partition for every possible filter value at Satellite imagery startup
- Recluster a pilot table and measure read/write behavior
Explanation
Correct Answer
D:Recluster a pilot table and measure read/write behavior provides a bounded way to introduce the approved solution into land_cover_observations_south and detect an early mismatch. The existing signal is query profile shows increased file scanning despite healthy worker utilization; a staged change protects the service requirement (performance optimization must adapt to predicate patterns) and makes rollback practical.
Incorrect Answers
A:Choose suitable liquid clustering keys and supported optimization maintenance is a plausible lasting design once chosen, but it does not perform the controlled implementation step at this stage. In the land_cover_observations_south scenario, the observed evidence is that query profile shows increased file scanning despite healthy worker utilization; the requirement remains: performance optimization must adapt to predicate patterns.
B:Compare representative query scan metrics and results before and after is a one-time acceptance check. It does not supply the controlled implementation step for land_cover_observations_south; a passing test cannot substitute for the specific task now required.
C:Extreme partitioning creates metadata overhead. The proposed action (Add a new physical partition for every possible filter value at Satellite imagery startup) does not meet the requirement that performance optimization must adapt to predicate patterns, nor does it constitute the controlled implementation step.
Question 388
A data engineer at Public weather agency is responsible for station observation files. The pipeline task invocation issue is that station_observation_files_island Spark Declarative Pipeline is managed separately and not part of the daily job. The supporting evidence is that analytics runs before the pipeline produces its updated streaming table. The engineer must ensure that job orchestration must wait for pipeline update completion. The new approach is deployed. The current task is to prove correct output and authorized behavior, not just successful installation. What evidence establishes that correct output is maintained?
- Trigger a full job and verify pipeline completion precedes analytics
- Inspect pipeline identity, job task settings and downstream dependencies for station_observation_files_island
- Assume the pipeline auto-refreshes before every dashboard query at Public weather agency
- Attach the governed pipeline to the job and pilot the execution graph
Explanation
Correct Answer
A:Trigger a full job and verify pipeline completion precedes analytics directly tests the behavior that should change after the correction. With the observed evidence (analytics runs before the pipeline produces its updated streaming table), the acceptance result must demonstrate actual data or permission correctness, while retaining the requirement that job orchestration must wait for pipeline update completion.
Incorrect Answers
B:Inspect pipeline identity, job task settings and downstream dependencies for station_observation_files_island could clarify the original fault, but the available evidence already establishes its scope; it is not the post-change acceptance test now requested. The station_observation_files_island workflow still requires that job orchestration must wait for pipeline update completion.
C:Uncontrolled refresh timing does not guarantee dependency order. The proposed action (Assume the pipeline auto-refreshes before every dashboard query at Public weather agency) does not meet the requirement that job orchestration must wait for pipeline update completion, nor does it constitute the post-change acceptance test.
D:Attach the governed pipeline to the job and pilot the execution graph may introduce a correction, but the question does not ask for installation or migration. A rollout alone cannot replace the post-change acceptance test, especially given the evidence that analytics runs before the pipeline produces its updated streaming table.
Question 389
At Online apparel cooperative, the bundle environment promotion isolation workflow handles customer order changes. The problem is that customer_order_changes_west test run overwrites production tables because both deployment targets share one catalog. Evidence: resolved bundle targets point to the same UC prefix. Constraint: development tests must not mutate production data. The first acceptance run passed. The current task is to detect future regressions and changes over time. Which monitoring approach will detect newly emerging defects?
- Use identical production destinations and hope developers avoid dangerous input at Online apparel cooperative
- Run destructive test inputs and verify production table remains unchanged
- Monitor cross-environment writes and unexpected permissions for customer_order_changes_west
- Segregate dev/test/prod catalog settings using bundle target overrides
Explanation
Correct Answer
C:Monitor cross-environment writes and unexpected permissions for customer_order_changes_west creates recurring visibility into the failure mode (customer_order_changes_west test run overwrites production tables because both deployment targets share one catalog). Unlike a single successful test, the measure can reveal drift, lag, or new failures after later source and deployment changes while development tests must not mutate production data.
Incorrect Answers
A:Shared output targets defeat environment isolation. The proposed action (Use identical production destinations and hope developers avoid dangerous input at Online apparel cooperative) does not meet the requirement that development tests must not mutate production data, nor does it constitute continuing operational detection.
B:Run destructive test inputs and verify production table remains unchanged is a one-time acceptance check. It does not supply continuing operational detection for customer_order_changes_west; a passing test cannot substitute for the specific task now required.
D:Segregate dev/test/prod catalog settings using bundle target overrides is a plausible lasting design once chosen, but it does not perform continuing operational detection at this stage. In the customer_order_changes_west scenario, the observed evidence is that resolved bundle targets point to the same UC prefix; the requirement remains: development tests must not mutate production data.
Question 390
Consider the clinical_appointment_reports_island workload at Regional hospital network: clinical_appointment_reports_island transformation intermittently fails with executor out-of-memory. Inspection found that Spark UI shows large skewed partitions and executor lost errors. The governed outcome must ensure that the job must process full input safely without excluding valid rows. The failure and requirements have been diagnosed; the team must select the lasting pipeline or governance approach. Which data-engineering approach resolves the documented weakness?
- Choose balanced partitioning and appropriate executor memory for the workload
- Inspect task partition sizes, execution plan and memory overhead for clinical_appointment_reports_island
- Filter out the largest partition without business approval at Regional hospital network
- Monitor OOM retries, failed executor count and memory utilization in clinical_appointment_reports_island
Explanation
Correct Answer
A:Choose balanced partitioning and appropriate executor memory for the workload is the intended durable approach for clinical_appointment_reports_island: it addresses the verified problem (clinical_appointment_reports_island transformation intermittently fails with executor out-of-memory) while preserving the required behavior (the job must process full input safely without excluding valid rows). A diagnostic or monitoring step alone would not create this target-state behavior.
Incorrect Answers
B:Inspect task partition sizes, execution plan and memory overhead for clinical_appointment_reports_island could clarify the original fault, but the available evidence already establishes its scope; it is not the target approach now requested. The clinical_appointment_reports_island workflow still requires that the job must process full input safely without excluding valid rows.
C:Dropping data to avoid oom violates completeness. The proposed action (Filter out the largest partition without business approval at Regional hospital network) does not meet the requirement that the job must process full input safely without excluding valid rows, nor does it constitute the target approach.
D:Monitor OOM retries, failed executor count and memory utilization in clinical_appointment_reports_island would help detect future recurrence, but metrics alone do not deliver the target approach. The clinical_appointment_reports_island requirement is that the job must process full input safely without excluding valid rows.